Latching means for electromagnetic devices



Jan. 25, 1944. B. c. WELLS 2,340,092

LATCHING MEANS FOR ELECTROMAGNETIC DEVICES Filed'May 15, 1941 I 1d] 0 I l 4 INVENTOR Era/0e C Neils.

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ATTORNEY Patented Jan. 25, 1944 LATCHING MEANS FOR ELECTROMAGNETIC DEVICES Bruce 0. Wells,

inghouse Electric vania Pittsburgh, Pa., assignor West- & Manufacturing Company, East Pittsburgh, Pa.,

a corporation of Pennsyl- Appilcation May 15, 1941, Serial No. 393,686 4 Claims. (01. 115-336) My invention relates to electromagnetic devices and more particularly to latching means for electromagnetic contactors, relays, etc.

Latching devices for the armatures and other movable elements of electromagnetic devices such as contactors and relays are well known in the art. Such devices of the prior art are oomphcated and expensive requiring extra trip coils or manually operable mechanical tripping means.

Such devices, because of their complexity, and

often for other reasons, are not very reliable in operation, get out of order easily, add to the cost of the equipment, and generally have a low efficiency.

One object of my invention is to eliminate the mentioned shortcomings of the prior art. 7

Another object of my invention is the provision or latching means that are operable from the same coil used to actuate the armature.

mechanical parts that are subject to only small frictional loads.

Othe objects of my invention will become more apparent from a study of the following specification and the drawing, in which:

Figure 1 is a side view of a latchedein relay showing parts of my invention in section, and showing the position of the elements when the relay is not energized;

Fig. 2 shows the position of the elements after a first energisati'on of the relay coil;

Fig. 3 shows the position of the elements upon a second energization of the relay; and

Figs. 4, 5 and 6 show side views of a modified construction of my invention with the respective figures showing operating positions similar to the operating positions shown in Figs. 1', 2 and 3, respectively.

In Fig. Lthe magnet is designated by M, the armature by A and the coil 'by C. The actuation of the armature operates s table switches, in themselves no part of this invention, coupled to the lower'end oi! the armature. In practice the armature, in its operatic slides vertically in a pair oi! readily removable non-magnetic guides (not shown) disposed longitudinally of the coil axis. The two laminaticns 3 at each side 0! the I5 is bent back as shown and the armature are disposed beyond the outer face or the magnet and are made longer so as to straddie the portion 2 of the magnet. The side lam.- ination at the remote side of the armature A is the only one shown for purposes of clarity.

Between these elongations of the outer laminations, the generally .U-shaped latch member I is rather loosely pivotally mounted onbearing pin 5. The latch member has a top connecting portion 6 forming the base of the U and the sides l, of flat material of generally trapezoidal shape as shown, form the legs of the U. Stop pins 8 and 9 are rigidly mounted in the sides of the latching member and connect the sides.

A latch-releasing actuating member ID of a shape'as shown is loosely mounted on the hear-- ing pin 5.

v The magnet M has one of its sides cut as shown at H and I2 to form a movable armature l3 pivotally mounted at 14. To this armature, the lever l5, generally in the shape of a crucifix, is rigidly attached. The top portion l6 ofthis lever arms l8 are also bent back or to the'left of the pivot axis at H by a small amount as shown. The arms l8 rest in the pivot notch H of the side bars 20, for the magnet and are thus pivoted at thispoint. The tension springs 2| are connected to the ends of the arms l8 and to the magnet frame so that the springs will'bias the armature l3 to rotate counterclockwise even whenthe armature is in the position shown in Fig. 1.

The operation is as follows: Ulpon energization of the coil 0 the armature A moves vertically upward and the latch member 4, by the upward movement of bearing pin 5, is moved from the position shown in Fig. 1 to that shown in Fig. 2. After the coil C is deenergized, the armature does not dropbut the latch member 4, now resting firmly on the magnet frame, thus latches the armature in the up position.

The deenergization of coil C releases armature l3 and the springs 21 move this armature counterclockwise. The top portion is, temporarily tilting the latch releasing member Ill clockwise, moves under the upper right-hand end of ID, as shown in Fig. 2.

When the coil C is again energized, armature i3 is actuated clockwise on pivot l4 and the top portion l6, engaging the under side of the upper right-hand end of member ID, thus moves the latch member 4 counterclockwise on hearing pin 5. This is'so because the member if! is restrained aaginst counterclockwise movement on latch member 4 by the stop pin 8.

The latch member I is thus moved to the position shown in Fig. The moment the coil C is deenergized, the armature A drops and the stop pin 9 engages the underside of top portion 16 and the armature I3 is held in the position shown in Fig. 1.

Since armature I3 is very much lighter than armature A, the drop-out flux is much lower for armature l3 than for armature A. This means that armature A is always released sooner than armature I3. There is thus no danger of the movement of top portion IE to the position shown in Fig. 2 before armature A has dropped. Further, the leakage flux is suflicient to hold armature 13 long enough to make certain of 'correct operation.

My invention thus consists of a mechanical latching device as a part of a magnetic structure, which is unique in that none of the parts is under load during either closing or opening of the device. It is also unique in that the same magnet is used for closing and opening. The main magnetic circuit is used to operate a load such as electrical contacts, and the tripping operation is performed by an auxiliary armature which may work either from magnetic leakage or as a part of the main magnetic circuit.

The roller 22 is merely an antifriction member for the purpose of preventing any sticking when the armature A begins to drop. This sticking tendency is not great, and a suitably rounded portion on the latch member 4 at the region where the roller is shown will often be suflicient.

In view of the detailed description of the structure and operation of the embodiment shown in Figs, 1, 2 and 3, a detailed discussion of the modification shown in Figs. 4, 5 and 6 is thought not necessary. A brief statement of its structure and operation will suffice.

The armature A carries the supporting pin 5'- for latch releasing member ID and latch 4'. Spring 30 is a weak tension spring for normally holding the armature 43' in the position shown in Fig. 5 when the coil is deenergized. The small compression spring 3| holds member ID in a given position on latch 4'. The operating lever 32 is fixed to armature i3.

Th; operation is as follows:

When coil C is energized, armature A moves up and stops against the magnet structure at 33. Armature l3 seals in position and I0 and 4' rotate to the position shown in Fig. 5.

When the coil C is deenergized, 4' strikes the top of the magnet and the armature A is latched in the up position. Lever 32 moves to the left about pivot l4 striking member ID, causing it to rotate on pin temporarily compressing spring 3| and allowing the lever to take the position shown in Fig. 5.

When the coil is energized for a second time, armature A is moved up, relieving d of its load and armature l3 moves to its sealing position, and in doing so, lever 32 through l0 actuates latch 4' to the position shown in Fig. 6. When the coil C is next deenergized, the armature A drops.

The two species shown and described are illustrative of my invention and are not to be taken in a limiting sense. The claims hereto appended define the scope of my invention.

I claim as my invention:

1. In an electromagnetically operable device, in combination, a magnetic circuit including a generally rectangularly shaped frame having, two vertical sides and two horizontal sides and an opening in the lower horizontal side and a pivotally mounted armature included in one of the vertical sides and a main armature disposed to move through the opening, a coil disposed within the frame and encircling the main armature to actuate the armature, a pivotally mounted latch structure mounted at one end of the main armature and adapted to latch the main armature into an actuated position upon a first energization of the main coil, means actuated by the pivotally mounted armature and operating on the latch structure for releasin the main armature after a second energization of said coil.

2. In an electromagnetic device, a frame, a vertically movable armature having a lower end position and an upper end position mounted in the frame, a coil for actuating the armature, a pendulus type latch member pivotally mounted at the upper end of the armature and disposed to take a vertical position upon movement of the armature to its upper end position to thereby engage the frame to latch the armature in its upper end position upon an energization of said coil, and a horizontally movable armature operable upon a second energization of said coil for tripping said latch to thus release the vertically movable armature.

3. In an electromagnetic device, in combination, a generally rectangular frame comprising a magnetic circuit, said frame having two vertical sides and two horizontal sides, a coil disposed in the frame, so as to have its axis parallel to the vertical sides, a main armature disposed centrally of the coil and mounted to move vertically upward to an actuated position when the coil is energized and to move vertically downward when the coil is deenergized, a pendulus latching member connected to the upper end of the main armature and disposed to move to a vertical position to abut against the frame to latch the armature into its actuated position upon a first energization of the coil, a second armature constituting part of one of the vertical side members of the frame adapted to move said pendulus latching member out of its vertical position to release the main armature from its latched position upon a second energization of said coil.

4. In an electromagnetic device, in combination, a generally rectangular frame comprising a magnetic circuit, said frame having two vertical sides and two horizontal sides, a coil disposed in the frame, so as to have its axis parallel to the vertical sides, a main armature disposed centrally of the coil and mounted to move vertically upward to an actuated position when the coil is energized and to move vertically downward when the coil is deenergized, a pendulus latching member connected to the upper end of the main armature and disposed to move to a vertical position to abut against the frame to latch the armature into its actuated position upon a first energiaztion of said coil, a second armature pivotally mounted at its upper end, said second armature constituting part of one of the vertical side members of the frame, means for biasing the second armature out of the plane of the ver tical side member of which it is a. part, and a member on the second armature for moving the pendulus latching member out of vertical posltion to release the main armature from its latched position, said last named member being actuated, upon a second energization of the coil by reason of the movement of the second armature into the plane of the frame by the second energization of said coil.

BRUCE C. WELLS. 

